1. Field of the Invention
The present invention relates to a intranasal (via nasal route) pharmaceutical composition comprising calcitonin as an active ingredient and more particularly, to an excellent calcitonin intranasal composition containing a specific absorption enchancer.
2. Description of the Related Art
Calcitonin is a polypeptide hormone having various pharmaceutical activities which is used for treatment of osteoporosis, hypercalcemia, Paget's disease, etc.
Calcitonin is decomposed in the gastrointestinal tract by digestive juice, like ordinary pharmacologically active peptides so that oral administration of calcitonin is not available therapeutically. In addition, due to poor absorption, calcitonin is generally administered by injection. However, injections are extremely painful and this route of administration is not used. Thus inconvenience and a cost problem encountered.
Recently, it has been found that by application of calcitonins via intranasal route, effects simmilar to conventional intramuscular injection are exhibited and, various compositions of intranasal calcitonin composition have been proposed. However, a polypeptide having a large molecular weight such as calcitonin is absorbed intranasally only with difficulty. Therefore, as absorption enhancers, for example, surface active agents are generally incorporated (Published Unexamined Japanese patent application Nos. 89619/84 and 130820/84). In this case, both amphoteric and cationic surface active agents are employed; it is said, however, that nonionic type surface active agents, inter alia, polyoxyethylene lauryl ether, are particularly excellent in absorption acceleration properties. However, this polyether type surface active agent exhibits the undesirable property of destroying the nasal membrane. Thus, the surface active agent has a strong toxicity to tissue and is therefore undesirable for use as it is.